What is the water clarity of Clear Lake?

Clear Lake has a Secchi depth (water clarity) of 1.5 feet. That is poor clarity, indicating heavy algae or sediment.

Does Clear Lake have an algae problem?

Clear Lake has a chlorophyll-a (algae) level of 44 µg/L. That is high — the lake is at meaningful risk of harmful algal bloom advisories in summer.

How Clean Is Clear Lake?

Q: Is Clear Lake polluted?

Clear Lake shows pollution indicators consistent with nutrient over-enrichment (typically phosphorus from agricultural runoff, fertilizer, or failing septic systems). Its has nutrient and algae measurements on record from state and federal monitoring, reflecting elevated nutrient and algae levels.

Clear Lake is algae-prone, with a higher bloom risk in warm months. Its nutrient and algae readings come from EPA monitoring data. Water clarity (Secchi depth): 1.5 ft. Phosphorus: 90.5 µg/L. Chlorophyll-a (algae): 44 µg/L. Trophic State Index: 69.

Cleanliness Snapshot

Metric	Clear Lake	Minnesota avg
Water Clarity (Secchi)	1.5 ft	—
Phosphorus	90.5 µg/L	<30 = clean
Chlorophyll-a (Algae)	44 µg/L	<10 = clean
Trophic State Index	69	<50 = clean

How does Clear Lake compare?

Clear Lake's readings run above the Minnesota state average. It ranks #4 of 6 lakes in Jackson County by water quality score. Multi-year monitoring data shows water quality is declining based on 2 years of records.

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More on Clear Lake

Is Clear Lake safe for swimming? →What fish are in Clear Lake? →Is Clear Lake polluted? →Full water quality report →Jackson County lakes →Cleanest lakes in Jackson County →Cleanest lakes in Minnesota →